Patients who require non-emergent, uncomplicated target lesion revascularisation after percutaneous coronary intervention (PCI) have a significantly increased risk of mortality compared with patients who do not require such revascularisation. Furthermore, this risk continued to be significant after excluding patients who experienced a myocardial infarction during follow-up.
Tullio Palmerini (Polo Cardio-Toraco-Vascolare, Policlinico S Orsola, Bolgna, Italy) and others report in JACC: Cardiovascular Interventions that restenosis requiring target lesion revascularisation is “generally considered benign” (apart from when severe restenosis presents as acute myocardial infarction). However, they note that all repeat revascularisation procedures—whether PCI or coronary artery bypass grafting (CABG)—“carry the risk of potential periprocedural and late complications”. Furthermore, according to Palmerini et al, the clinical impact of target lesion revascularisation is not fully understood and has not been examined in large-scale studies. “We therefore investigated the association between non-emergent, uncomplicated target lesion revascularisation and mortality in a large cohort of patients included in randomised controlled trials,” the authors write.
Using patient-level data from 21 randomised trials, they identified 32,524 patients who either had a non-emergent, uncomplicated target vessel revascularisation (3,140) or who did not require any form of target lesion revascularisation. Patients who died on or the day after the index procedure were excluded as were patients who experience a myocardial infarction the day before, the same say or the day after the target vessel revascularisation procedure. The primary endpoint was all-cause mortality, with Palmerini et al noting that their primary objective was to “examine the relationship between non-emergent, uncomplicated target lesion revascularisation, and subsequent all-cause mortality at the longest follow-up time available”.
Overall, 193 deaths occurred in patients with some form of target vessel revascularisation—144 of which occurred in patients who underwent target lesion revascularisation and 49 occurred in patients with target vessel revascularisation but not target lesion revascularisation. The median follow-up point was 884 days. The authors report: “Patients with non-emergent, uncomplicated target lesion revascularisation had significantly higher rates of mortality than patients not undergoing target vessel. After adjustment for potential confounders, non-emergent uncomplicated target lesion revascularisation was an independent predictor of mortality (hazard ratio 1.23; p=0.02)”. However, target vessel revascularisation not in the target lesion did not significantly increase the risk of mortality.
Additionally, non-emergent target lesion revascularisation continued to be an independent predictor of mortality after patients (130) who presented with a myocardial infarction between one day and one month earlier were excluded. Palmerini et al comment that this suggests “other mechanisms in addition to myocardial infarction between target lesion revascularisation and mortality”.
Concluding their findings, they comment: “Further studies are required to determine the mechanisms underlying this observation, and whether new therapies to prevent restenosis (in addition to limit atherosclerosis progression) may improve the prognosis of patients with coronary artery disease undergoing PCI”.
Study investigator Gregg Stone (Columbia University Medical Center, New York, USA) told Cardiovascular News: “The mechanisms of increased mortality with target lesion revascularisation may relate to complications from the procedure itself, subsequent myocardial infarction due to recurrent target lesion revascularisation procedures or stent thrombosis, or indicate patients with unmeasured confounders of increased risk or in whom atherosclerosis or restenosis is likely to be progressive. Importantly, however, the risk of target lesion revascularisation from the present study is likely under-estimated as we excluded patients in whom target lesion revascularisation presented as an acute myocardial infarction, or in whom the target lesion revascularisation procedure itself resulted in a myocardial infarction.”